scholarly journals Wear Rate to Stainless Steel Pipe From Liquid-Solid Slurry

2016 ◽  
Author(s):  
Mark R. Duignan ◽  
Marissa M. Reigel ◽  
Kenneth J. Imrich ◽  
Michael L. Restivo ◽  
Mark D. Fowley
Keyword(s):  
Stainless Steel ◽  
Wear Rate ◽  
Operating Conditions ◽  
Flow Loop ◽  
Straight Pipe ◽  
Pipe System ◽  
Wear Rates ◽  
Test Flow ◽  
Flow Stream

The United States Department of Energy is building a Waste Treatment Plant (WTP) at the DOE Hanford Site in the state of Washington to process stored radioactive wastes for long-term storage and disposal. The Savannah River National Laboratory (SRNL) is helping resolve technical concerns with the WTP, which are related to piping erosion/corrosion (wear). SRNL is assisting in the design of a flow loop to obtain long term wear that will use prototypic simulant chemistry, operating conditions, and materials for total wear rate. The challenge is to accurately measure slurry wear to a pipe wall thickness tolerance of ∼47 microns/year anywhere in the test flow loop in a timely manner. To help in the design of the flow loop a test was performed with a smaller loop, which contained many of the pipe fittings expected in WTP to determine where high wear locations exist. One aspect of this test was to understand the rate of wear to straight pipe and to protrusions from the surface of the pipe. Initially, wear to straight pipe was studied because wear in other flow loop situations, e.g., around bends, through tees, etc. will be higher. To measure such low wear rates requires sensitive measurement techniques. To that end, twelve wear coupons were placed in one section of the pipe system and at different protrusion heights into the flow stream. They were made of 316L stainless steel, which is the expected material of pipe to be utilized. From the wear coupons, an estimate of wear rate was obtained, as well as illustrating when a protrusion above a pipe surface no longer disturbs the flow streams with respect to slurry wear. It appears when a surface is just above the laminar sublayer it produces a wear rate equivalent to a surface with no protrusions. The slurry was a mixture of water and 30 wt% of sand, d50 ∼ 200 microns. The test flow conditions were a velocity of 4 m/s in a 0.07793-m inside diameter (3-inch, Schedule 40) pipe system, resulting in Reynolds number just above 3 × 105, i.e., turbulent flow at a temperature of 25°C. The wear was to a vertically oriented straight section of pipe that was 1.86 meter long. The twelve wear coupons were located on the inside surface starting from 10 diameters from the pipe entrance to 21 diameters, with a separation of 1-pipe diameter between each successive coupon. Furthermore, each set of two adjacent coupons were rotated 180 degrees apart which were then rotated 30 degrees from the next set to minimize disturbance to the flow for the downstream coupon. This paper describes the wear rates obtained, the effect of increasing a wear coupon’s protrusion into the flow stream, and the overall operation of the test apparatus.

scholarly journals Wear Locations in Stainless Steel Pipe Fittings From the Turbulent Flow of a Liquid-Solid Slurry

2015 ◽  
Author(s):  
Mark R. Duignan ◽  
Marissa M. Reigel ◽  
Kenneth J. Imrich ◽  
Michael L. Restivo ◽  
Mark D. Fowley
Keyword(s):  
Turbulent Flow ◽  
Measurement Techniques ◽  
The United States ◽  
Operating Conditions ◽  
Steel Pipe ◽  
United States Department ◽  
Flow Loop ◽  
Test Flow ◽  
Pipe Fittings

The United States Department of Energy (DOE) is building a Waste Treatment Plant (WTP) at the DOE Hanford Site in the state of Washington to process stored radioactive wastes for long-term storage and disposal. The Savannah River National Laboratory (SRNL) is helping resolve technical concerns with the WTP, which are related to piping erosion/corrosion (wear). SRNL is assisting in the design of a flow loop to obtain long term wear rates that will use prototypic simulant chemistry, operating conditions, and materials. The challenge is to accurately measure slurry wear to a pipe wall thickness tolerance of 47 microns/year anywhere in the test flow loop in a timely manner. A first step in such a test is to secure knowledge of high wear locations so that highly sensitive measurement techniques can be incorporated and properly located. Literature exists to help locate such wear locations in pipe and pipe fittings but most of the information deals with slurry flows that have significantly different velocities, different flows steams, e.g., steam, gas-liquid-solids, or made from different materials. To better estimate these high wear rate locations under the WTP conditions a separate pre-test flow loop was constructed and operated. This loop is referred to as the paint loop because it was internally coated with paint, which wears faster than the steel pipe, when a solids-laden slurry is circulated. The test flow conditions were a slurry velocity of 4 m/s in a 0.0762 -m (3-inch) Schedule 40 pipe system, resulting in Reynolds number just above 3 × 105, i.e., turbulent flow at a temperature of 25°C. The slurry was a mixture of water and sand, d50 ∼ 199 microns. This paper describes the test paint loop, its operation, and indicates the high slurry wear locations, as well as a comparison of those locations to existing literature sources.

Mid- to Long-Term Survivorship Analysis of a Second-Generation Highly Cross-Linked Polyethylene in Total Hip Arthroplasty

2020 ◽  
Vol 4 (03) ◽  
pp. 124-128
Author(s):  
David Yeroushalmi ◽  
Katherine A. Lygrisse ◽  
Mohamad Sharan ◽  
Nolan A. Maher ◽  
Joseph D. Zuckerman ◽  
...  
Keyword(s):  
Total Hip Arthroplasty ◽  
Wear Rate ◽  
Hip Arthroplasty ◽  
Second Generation ◽  
Abduction Angle ◽  
Linear Wear ◽  
Wear Rates ◽  
Total Hip

AbstractThe emergence of highly cross-linked polyethylene (HCLPE) has drastically improved survivorship of implants used in total hip arthroplasty (THA), as demonstrated by midterm outcomes. However, there is limited data evaluating long-term outcomes and wear rates of these liners. Therefore, the aim of this study is to evaluate the longest-to-date follow-up of a specific second-generation HCLPE liner, the progression of wear rate, and its relation to acetabular cup positioning. A retrospective study was conducted on patients who underwent THA between January 2001 and December 2005 using a specific second-generation HCLPE liner. Annual liner wear rate (mm/year) was calculated in this group as well as acetabular positioning through abduction angle (degrees). Failures and reason for failures such as periprosthetic fracture, dislocation, and osteolysis were noted when applicable. Forty hips of 35 patients were included in this study with a clinical and radiographic follow-up of 13.4 ± 2.2 years (range: 10.0–16.7 years). Linear and volumetric wear rates were calculated to be 0.037 ± 0.020 mm/year and 22.94 ± 12.07 mm3/year, respectively. No radiographic femoral or acetabular osteolysis was observed in any of the cases. One patient required revision due to complications unrelated to the liner. No significant relationship could be established for acetabular component abduction angle and linear wear rate (p = 0.690, Spearman's rho = 0.03). Our study demonstrates comparable liner wear rates to that of other second-generation HCLPE liners in long-term follow-up. The XLPE liner continues to exhibit minimal progression of linear wear when compared with previous midterm studies and maintains a low rate of postoperative complications requiring revision THA surgery. Further studies are warranted to assess long-term wear and survivorship between this specific liner and comparable HCLPE models.

Influence of Surface Treatment of High Carbon Steel on the Reciprocating Wear in Comparison With the 316 Stainless Steel

2009 ◽  
Author(s):  
U. D. Gulhane ◽  
Manish Roy ◽  
S. G. Sapate ◽  
S. B. Mishra ◽  
P. K. Mishra
Keyword(s):  
Stainless Steel ◽  
Carbon Steel ◽  
Wear Rate ◽  
High Carbon Steel ◽  
Composite Layer ◽  
High Carbon ◽  
Wear Rates ◽  
316 Stainless Steel ◽  
First Case ◽  
Reciprocating Wear

Diffusion treatments such as chromising and aluminising of high carbon steel results in the formation of Cr and Al rich layers on the surface. These layers will be responsible for formation of protective Cr2O3 and Al2O3 scale on exposure to corrosive environment. In view of extensive application of 316 Stainless Steel in biomedical engineering, present work is undertaken to examine the influence of diffusion treatment of high carbon steel on the reciprocating wear in Hank’s solution and to compare the same behavior with that of 316 SS. In order to achieve the above mentioned objectives, the wear rates of 316 SS, 304 SS, high carbon steel in aluminised and chromised condition have been evaluated. Though the general characteristics of the wear behavior, such as higher wear rate at higher load and at higher reciprocating speed, for all the materials are similar, aluminised and chromised high carbon steel exhibited best wear resistance especially at high and intermediate load. In simulated body fluid condition, 316 SS exhibited two different material removal mechanisms. In the first case, which is observed at higher load, material loss is by nucleation and propagation of crack. In the second mechanism which is prevalent at low and intermediate load, wear takes place by deterioration of composite layer formed on the surface by mixing the corrosion product and the substrate. Consequently it is noted that wear rate decreases with increase of hardness at higher load. At intermediate and at low load wear rate is less dependent of hardness.

ESTIMATION OF THE SPEED OF RO TION OF THE SPEED OF ROTATION OF GEARS IN OIL TION OF GEARS IN OIL DEPENDING ON THE LOAD

2020 ◽  
Vol 2020 (4) ◽  
pp. 192-199
Author(s):  
N Mirzayev ◽  
◽  
B Qurbonov
Keyword(s):  
Wear Rate ◽  
Friction Force ◽  
Friction Surface ◽  
Normal Pressure ◽  
Operating Conditions ◽  
Tabular Form ◽  
Wear Rates ◽  
Small Cracks ◽  
Contact Surfaces

This article shows the wear and the amount of load that occurs in the gears under different loads and under different operating conditions of the contact surfaces, and is given by the formulas. The values of loads and wear rates on gears are given in tabular form based on curves. According to the results of the study, an increase in the load value affects the wear rate, as well as the load values q = 100; 200; 300; 400; at N/mm, a decrease in the wear rate was found. The load concentration and accumulation of dislocations in the material, their approach and appearance of cracks, as well as the deep propagation of small cracks on the metal that occur mainly on the friction surface under the influence of normal pressure and friction force are studied.

Effect of WC Grain Size and Content on Erosive Wear of Manual Arc Welded Hardfacings with Low-Carbon Ferritic-Pearlitic Steel or Stainless Steel Matrix

2016 ◽  
Vol 674 ◽  
pp. 213-218 ◽  
Author(s):  
Egidijus Katinas ◽  
Maksim Antonov ◽  
Vytenis Jankauskas ◽  
Remigijus Skirkus
Keyword(s):  
Grain Size ◽  
Stainless Steel ◽  
Wear Resistance ◽  
Kinetic Energy ◽  
Wear Rate ◽  
Erosive Wear ◽  
Impact Angle ◽  
Steel Matrix ◽  
Low Carbon ◽  
Wear Rates

The erosive wear resistance of manual arc welded hardfacings with low-carbon or stainless steel matrix, varied WC grain size (0.23-0.61 mm) and varied WC content (max. 40 wt. %) was studied. Electrodes were produced by JSC “Anykščių varis“ company (Lithuania). Testing was performed according to GOST 23.201-78 standard using the Centrifugal Accelerator of Kleis (CAK). Test parameters were as following: room temperature; silica sand with particles size 0-0.6 mm; particle impact velocity – 10, 30, 50 and 80 ms-1; impact angles – 30° and 90°.It was found that there is only minor (usually not more than 2 times) effect of WC grain size and content on erosive wear of studied hardfacings. There is strong effect of velocity on wear rate. The graph showing the effect of abrasive particle‘s kinetic energy on wear rate is provided. It was found that the wear rate increases 2.8 times faster than kinetic energy of abrasive particles. The wear resistance of coatings could be improved by addition of WC when hardfacing is tested with impact angle of 30°. However, for impact angle of 90° the addition of WC into hardfacing has no effect or is even detrimental (leading to the increase in wear rate). The hardfacings with WC grain size in the range from 0.14 to 0.27 mm have the lowest wear rates during testing with impact angle of 30°. A discussion of the wear mechanisms for the hardfacings is provided, based on data and observations obtained by using scanning electron microscopy.

Wear Rates of Resin Composites

2013 ◽  
Vol 38 (2) ◽  
pp. 226-233 ◽  
Author(s):  
WW Barkmeier ◽  
RL Erickson ◽  
MA Latta ◽  
TM Wilwerding
Keyword(s):  
Stainless Steel ◽  
Composite Materials ◽  
Wear Rate ◽  
Loss Rate ◽  
Resin Composite ◽  
Linear Wear ◽  
Resin Composites ◽  
Volume Loss ◽  
Wear Rates ◽  
Significant Difference

SUMMARY A laboratory study was conducted to examine the wear of resin composite materials using a generalized wear simulation model. Ten specimens each of five resin composites (Esthet•X [EX], Filtek Supreme Plus [SP], Filtek Z250 [Z2], Tetric EvoCeram [EC], and Z100 Restorative [Z1]) were subjected to wear challenges of 100,000, 400,000, 800,000, and 1,200,000 cycles. The materials were placed in cylinder-shaped stainless-steel fixtures, and wear was generated using a flat stainless-steel antagonist in a slurry of polymethylmethacrylate beads. Wear (mean facet depth [μm] and volume loss [mm3]) was determined using a noncontact profilometer (Proscan 2000) with Proscan and ProForm software. Statistical analysis of the laboratory data using analysis of variance and Tukey's post hoc test showed a significant difference (p<0.05) for mean wear facet depth and volume loss for both the number of cycles and resin composite material. Linear regression analysis was used to develop predictive wear rates and volume loss rates. Linear wear was demonstrated with correlation coefficients (R2) ranging from 0.914 to 0.995. Mean wear values (mean facet depth [μm]) and standard deviations (SD) for 1200K cycles were as follows: Z1 13.9 (2.0), Z2 26.7 (2.7), SP 30.1 (4.1), EC 31.8 (2.3), and EX 67.5 (8.2). Volume loss (mm3) and SDs for 1200K cycles were as follows: Z1 0.248 (0.036), Z2 0.477 (0.044), SP 0.541 (0.072), EC 0.584 (0.037), and EX 1.162 (0.139). The wear rate (μm) and volume loss rate (mm3) per 100,000 cycles for the five resin composites were as follows: wear rate Z1 0.58, EC 1.27, Z2 1.49, SP 1.62, and EX 4.35, and volume loss rate Z1 0.009, EC 0.024, Z2 0.028, SP 0.029, and EX 0.075. The generalized wear model appears to be an excellent method for measuring relative wear of resin composite materials.

scholarly journals In-vivo-wear in composite and ceramic full mouth rehabilitations over 3 years

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Gintare Burian ◽  
Kurt Erdelt ◽  
Josef Schweiger ◽  
Christine Keul ◽  
Daniel Edelhoff ◽  
...  
Keyword(s):  
Wear Rate ◽  
Tooth Wear ◽  
Occlusal Contact ◽  
Wear Rates ◽  
Recall Time ◽  
Cad Cam ◽  
The Mean ◽  
Posterior Restorations

AbstractThe aim of this study was to quantify and to compare the wear rates of premolar (PM) and molar (M) restorations of lithium disilicate ceramic (LS2) and an experimental CAD/CAM polymer (COMP) in cases of complex rehabilitations with changes in vertical dimension of occlusion (VDO). Twelve patients with severe tooth wear underwent prosthetic rehabilitation, restoring the VDO with antagonistic occlusal coverage restorations either out of LS2 (n = 6 patients, n = 16 posterior restorations/patient; N = 96 restorations/year) or COMP (n = 6 patients; n = 16 posterior restorations/patient; N = 96 restorations/year). Data was obtained by digitalization of plaster casts with a laboratory scanner at annual recalls (350 ± 86 days; 755 ± 92 days; 1102 ± 97 days). Each annual recall dataset of premolar and molar restorations (N = 192) was overlaid individually with the corresponding baseline dataset using an iterative best-fit method. Mean vertical loss of the occlusal contact areas (OCAs) was calculated for each restoration and recall time. For LS2 restorations, the mean wear rate per month over 1 year was 7.5 ± 3.4 μm (PM), 7.8 ± 2.0 μm (M), over 2 years 3.8 ± 1.6 µm (PM), 4.4 ± 1.5 µm (M), over 3 years 2.8 ± 1.3 µm (PM), 3.4 ± 1.7 µm (M). For COMP restorations, the mean wear rate per month over 1 year was 15.5 ± 8.9 μm (PM), 28.5 ± 20.2 μm (M), over 2 years 9.2 ± 5.9 µm (PM), 16.7 ± 14.9 µm (M), over 3 years 8.6 ± 5.3 µm (PM), 9.5 ± 8.0 µm (M). Three COMP restorations fractured after two years and therefore were not considered in the 3-year results. The wear rates in the LS2 group showed significant differences between premolars and molars restorations (p = 0.041; p = 0.023; p = 0.045). The wear rates in COMP group differed significantly between premolars and molars only in the first two years (p < 0.0001; p = 0.007). COMP restorations show much higher wear rates compared to LS2. The presented results suggest that with increasing time in situ, the monthly wear rates for both materials decreased over time. On the basis of this limited dataset, both LS2 and COMP restorations show reasonable clinical wear rates after 3 years follow-up. Wear of COMP restorations was higher, however prosthodontic treatment was less invasive. LS2 showed less wear, yet tooth preparation was necessary. Clinicians should balance well between necessary preparation invasiveness and long-term occlusal stability in patients with worn dentitions.

Development of Correlations for Predicting the Slurry Erosion of Ductile Materials

2011 ◽  
Vol 133 (3) ◽  
Author(s):  
Girish R. Desale ◽  
Bhupendra K. Gandhi ◽  
S. C. Jain
Keyword(s):  
Stainless Steel ◽  
Wear Rate ◽  
Ductile Material ◽  
304L Stainless Steel ◽  
Erosion Wear ◽  
Slurry Erosion ◽  
Material Loss ◽  
Aisi 304L ◽  
Wear Rates ◽  
Steel Aisi

Material loss due to erosion is a serious problem associated with the flow of solid-liquid mixtures. In the present work, erosion wear tests have been carried out in a slurry pot tester for seven different ductile type materials namely aluminum alloy (AA6063), copper, brass, mild steel, AISI 304L stainless steel, AISI 316L stainless steel, and turbine blade grade steel using three different erodents namely, quartz, alumina, and silicon carbide. Experiments have been performed at different orientation angles of target material at the velocities of 3, 6, and 8.33 m/s for solid concentrations of 10%, 20%, and 30% (by weight) and particle sizes of 363, 550, and 655 μm. The contribution of cutting wear in the total wear of ductile material at various orientation angles has been determined. It is observed that the maximum cutting wear angle for the ductile material depends on its hardness and a correlation is developed for its prediction. Also a methodology is proposed for estimation of the total erosion wear rate as a contribution of cutting and deformation wear rates. It is seen that this procedure results in an error of ±18% in estimation of erosion wear rate for the present experimental data.

scholarly journals Long-term performance of oxidized zirconium on conventional and highly cross-linked polyethylene in total hip arthroplasty

SICOT-J ◽  
2020 ◽  
Vol 6 ◽  
pp. 10 ◽  
Author(s):  
Alberto V. Carli ◽  
Anay R. Patel ◽  
Michael B. Cross ◽  
David J. Mayman ◽  
Kaitlin M. Carroll ◽  
...  
Keyword(s):  
Total Hip Arthroplasty ◽  
Wear Rate ◽  
Hip Arthroplasty ◽  
Linear Wear ◽  
Wear Rates ◽  
Linear Wear Rate ◽  
Total Hip ◽  
Oxidized Zirconium

Introduction: Polyethylene wear and subsequent osteolysis remain obstacles to the long-term survivorship of total hip arthroplasty (THA). Highly cross-linked polyethylene (XLPE) with radical quenching represents a massive leap forward with dramatically improved wear rates compared to ultra-high molecular weight polyethylene (UHMWPE). In this study we evaluate the wear of UHMWPE and XLPE coupled with oxidized zirconium (OxZr) femoral heads. Methods: A longitudinal, retrospective analysis was performed identifying consecutive patients who received a 28-mm OxZr-on-polyethylene primary THA from 2003 to 2004 by a single, high-volume arthroplasty surgeon. Patients were divided into two groups: those that received (1) UHMWPE liner and (2) a highly XLPE liner. Patients were included if clinical follow-up was complete to 2014 or later. Radiographic analysis was performed by two blinded observers. Measures included cup position, annual linear wear rate, and presence of osteolysis. Pairwise comparisons, correlations, and inter-rater reliability were calculated. Results: Eighty patients were in the UHMWPE group with an average follow-up of 10 ± 1.23 years and 88 patients in the XLPE group with an average of 10 ± 1.03-year follow-up. Average age (68) was similar between groups (p = 0.288). Observer reliability was excellent for cup abduction (ICC = 0.940), anteversion (ICC = 0.942), and detection of osteolysis (ICC = 0.811). Annual linear wear rates were significantly higher (p = 1 × 10−19) with UHMWPE (0.21 ± 0.12 mm/year) compared to XLPE (0.05 ± 0.03 mm/year). Linear wear rate was significantly correlated to decreasing acetabular abduction (p = 0.035). Osteolysis was noted only in the UHMWPE group, with 17 patients (21.2%) exhibiting acetabular osteolysis and 37 (46.3%) patients exhibiting femoral osteolysis. Conclusions: OxZr coupled with XLPE showed minimal wear and no osteolysis at 10-year follow up. The yearly linear penetration rate is similar to that seen in other studies of XLPE THA. A careful longitudinal follow-up will be required to determine if advanced bearings such as OxZr or ceramic can show improved performance in the second decade of implantation.

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